Dickens portrays prisons as taking advantage of the poor, when society should be providing for them.
Dickens wrote this book with a definite social message in mind. In Stave One, Scrooge is confronted with two men collecting for the poor. Scrooge accosts them by asking if the prisons are operational, and specifically if the Poor Law is in effect.
“Are there no prisons?” asked Scrooge.
“Plenty of prisons,” said the gentleman, laying down the pen again.
“And the Union workhouses?” demanded Scrooge. “Are they still in operation?”
“They are. Still,” returned the gentleman, “I wish I could say they were not.”
“The Treadmill and the Poor Law are in full vigour, then?” said Scrooge.
“Both very busy, sir.” (Stave 1)
Scrooge is referring specifically to a law that Dickens often decried. In England, the Poor Law created workhouses where the poor, including orphans, were worked hard and nearly starved to death (as he portrayed in Oliver Twist), and debtor’s prisons where adults who could not pay their bills were thrown to rot. How do you pay back your debts if you are in prison?
The hopelessness of the Poor Law and the terrible economic conditions of the poor are decried by Dickens in general throughout the book. His main goal is to get people to stop looking the other way. Bob Cratchit, he argues, is abused by his employer, who underpays and overworks him and is not even aware that he has a ton of children at home and one that is crippled.
Specifically, Dickens wants people who have to stop being heartless and give to those who do not. Dickens tells us, through the Ghost of Christmas Present, that the conditions of the poor are caused by society. No education and poverty are to blame. When Scrooge asks whose children the ghost has, he is told point blank that the children (and thus their problems) belong to all of us.
“They are Man's,” said the Spirit, looking down upon them. “And they cling to me, appealing from their fathers. This boy is Ignorance. This girl is Want. Beware them both, and all of their degree; but most of all beware this boy, for on his brow I see that written which is Doom, unless the writing be erased. Deny it!” (Stave 2)
Dickens points out that the bigger problem is ignorance, not poverty. Ignorance is a problem created by a society that throws away its children and its poor and does not educate them. To Dickens, it was clear that universal education was a responsibility of the government. If you do not educate the children, you are creating a clear path from the streets to the prisons. Don't education society's children, and you bring doom to us all.
Over the course of the book, Scrooge goes from seeing a "surplus population" to seeing Cratchit's family. He realizes that the poor are people too. Dickens is trying to accomplish the same thing for his readers, by giving the prison population, the workhouse and debtor's prison occupants, faces and personalities. He brings them to life.